In general, an electronographic image forming system, for example, a copier, a facsimile, a printer, etc., includes an image forming mechanism, an ejection tray, and a finisher. The image forming mechanism may form an image, such as a toner image, on a sheet of a recording medium (e.g. transfer material). After images are formed, the sheets may be sent to the finisher that may perform post-processing, for example, aligning, sorting, stapling, and/or punching of recording mediums.
However, it is inappropriate to staple the sheets when the finisher receives a larger amount of sheets than it has the capacity to staple or when only one recording medium is sent to the finisher. In such cases, the finisher may eject the sheets without stapling.
An example finisher may include a stapler to staple sheets, a stapling determination unit to determine whether or not stapling is appropriate, and an ejection tray. The stapling determination unit may include a unit to determine whether or not the number of transfer materials exceeds the capacity of the stapler. When the finisher determines that the stapling of the transfer materials is inappropriate, the finisher may eject the sheets onto the ejection tray without stapling.
However, use of glossy sheets in an image forming system has been increasing due to an increased demand for photo image forming. The glossy sheets have lower friction force and are more slippery. Therefore, it is difficult to tidily stack a large amount of glossy sheets on the ejection tray when the sheets are automatically ejected without being stapled. Further, failure in transporting the sheets (e.g. paper jam) may occur.